XML 32 R31.htm IDEA: XBRL DOCUMENT
v2.4.0.8

Commitments and Contingent Liabilities (Details) (USD $) In Thousands, unless otherwise specified | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2013 | Jun. 30, 2012 | Jun. 30, 2013 | Jun. 30, 2012
Commitments And Contingent Liabilities Details |  |  |  |
Treated | $ 762 | $ 775 | $ 1,523 | $ 1,494
Untreated | 515 | 516 | 1,121 | 1,128
Total Costs | $ 1,277 | $ 1,291 | $ 2,644 | $ 2,622

X
- Details
Name: | msex_CommitmentsAndContingentLiabilitiesDetailsAbstract
Namespace Prefix: | msex_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents cost of purchase of treated water. + References No definition available. + Details
Name: | msex_CostOfTreatedWater
Namespace Prefix: | msex_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Represents cost of purchase of untreated water. + References No definition available. + Details
Name: | msex_CostOfUntreatedWater
Namespace Prefix: | msex_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Cost of water purchased, may include any water related assessment. If water is bought on a unit volume basis, would also be considered as commodity costs. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.2) -URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688 + Details
Name: | us-gaap_CostOfPurchasedWater
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration